c#做的window服务如何每天9点定时发邮件？？

Question

        private DateTime LastSendTime = DateTime.Today;        private void timer1_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            DateTime now = DateTime.Now;
            if (now.Hour == 9)
            {
                TimeSpan span = now - LastSendTime;
                if (span.TotalHours > 1)//防止同一小时内重复发送
                {
                    LastSendTime = now;
                    SendMail();
                }
            }
        }

Answer 1

System.Timers.Timer t = new System.Timers.Timer(1000);
t.Elapsed += new System.Timers.ElapsedEventHandler(TimeElapse);
t.AutoReset = true;
t.Enabled = true;
public void TimeElapse(object source, System.Timers.ElapsedEventArgs e) 
        { 
            if(DataTime.Now.hour==9 && DataTime.Now.Minutes==3)或DateTime.Now.ToString("HHmm").Equals("0903")
             {//sendmail}
        } 

Answer 2

        private void timer1_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            DateTime now = DateTime.Now;
            //时间片太小，在系统警张情况下，不保证执行过程中被跳过去，所以分钟用>=3判断
            if (now.Hour == 9 && now.Minute >= 3)
            {
                TimeSpan span = now - LastSendTime;
                if (span.TotalHours > 1)//保证在9:03分以后只发送一次
                {
                    LastSendTime = now;
                    SendMail();
                }
            }
        }